(東北大學 材料與冶金學院， 沈陽 110006)
摘 要: 采用浸泡腐蝕實驗和電化學實驗研究了強化元素Cu含量的改變及不同時效制度對Al-Mg-Si合金晶間腐蝕敏感性的影響，并利用XRD和SEM對腐蝕產(chǎn)物的構成及形貌進行了分析與觀察。浸泡腐蝕實驗結果表明：在峰時效的狀態(tài)下，在0.5%Cu以上的合金中可觀察到明顯的晶間腐蝕，而且隨著Cu含量的增加，合金最大腐蝕深度增加；在欠時效狀態(tài)下，1%Cu以上的合金中觀察到了微弱的晶間腐蝕；在過時效狀態(tài)下，所有實驗合金均只出現(xiàn)點蝕。電化學實驗結果表明：隨著Cu含量的增加，合金的φcorr向正的方向變化，Jcorr增加，欠時效狀態(tài)下的φcorr比峰時效狀態(tài)下的負，腐蝕電流密度較小。
關鍵字: Al-Mg-Si合金； 晶間腐蝕； Cu含量； 時效
to intergranular corrosion of Al-Mg-Si alloys
（School of Materials and Metallurgy， Northeastern University，
Shenyang 110006， P.R.China）
Abstract: By the immersion corrosion tests and electrochemistry tests, the effects of changing Cu content and varying age treatments on the susceptibility to intergranular corrosion of Al-Mg-Si alloys have been studied. Phase structures of corrosion products were analyzed by XRD and the corrosion morphologies were observed by SEM.The results of immersion corrosion tests show that obvious intergranular corrosion is detected on the alloys with over 0.5%Cu and the maximum corrosion depth increases with increasing Cu content after the precipitation treatment. Slight intergranular corrosion is found on the alloys with over 1%Cu after the under-aged treatment. Pitting is observed on all alloys after the over-aged treatment. Results of electrochemistry tests indicate that φcorr varies to positive and Jcorr increases with increasing Cu content. Theφcorr and Jcorrunder the under-aged condition are more negative and smaller respectively than those under the precipitation-age condition.
Key words: Al-Mg-Si alloys； intergranular corrosion； Cu content； age
